Drum sander problem

[Aaron Hooks]

I recently bought a used General 24" dual drum sander. One problem I am having is the conveyor belt stopping suddenly. The result is groove where both drums continue spinning. If I flip the start/stop switch it will start again and run the board through the rest of the way.

This only seems to happen under load. I contacted General and they suggested replacing the circuit board that controls the conveyor motor. That didn't help. They sent me another one with a new switch - still have the problem.

Just wondering if this is unique to me?

Thanks!

[Matt Logana]

I recently bought a used General 24" dual drum sander. One problem I am having is the conveyor belt stopping suddenly. The result is groove where both drums continue spinning. If I flip the start/stop switch it will start again and run the board through the rest of the way.

This only seems to happen under load. I contacted General and they suggested replacing the circuit board that controls the conveyor motor. That didn't help. They sent me another one with a new switch - still have the problem.

Just wondering if this is unique to me?

Thanks!

A simple question, but one that might actually be effecting it: Have you ran multiple species? Is it only on a hardwood? Are you trying to shave too much off in one pass?

Thats the only thing I can think of... Stalling...

[Karl Card]

A simple question, but one that might actually be effecting it: Have you ran multiple species? Is it only on a hardwood? Are you trying to shave too much off in one pass?

Thats the only thing I can think of... Stalling...

Actually I do have a question when you say the belt stops, do you mean the belt is sliding or the motor that turns the belt is the reason for the belt stopping?


I am by far no expert but that is kind of where I was heading also.

I do know on my 16/32 that I have alwasy heard people complain about not enough power...... wow... mine has not stopped yet with teak, australian jarra, padauk and purpleheart...

[ed vitanovec]

I had a similar problem with my woodtech 26" dual drum sander, the tech support suggested replacig the board and switch. This took car of my problem, is your feed belt tight enough? Also check the brushes in the drive belt DC motor.

Regards!
Ed

[Aaron Hooks]

I appreciate all the feedback!

In regards to species. I have only had it stop since replacing the board and switch with western red cedar. Prior to that it happened with Red Oak as well. I have mostly run cedar through it because I have been making a lot of outdoor furniture. I know that material is not very dry and wondered if that caused a lot of back pressure on it. Yesterday I ran White Ash through and was very careful to take llght passes - didn't "stop"

The conveyor doesn't seem to slip - there is no noise that would indicate that and if I flip the switch it starts right up?

I will take a look at the brushes.

Thanks again everyone!:)

[Will Overton]

When I first set up my 16-32 the conveyor belt would slip occasionally. It turned out it wasn't tensioned properly. It didn't make any noise. Instead of listening the next time it happens, look at the drive roller and see if it is still turning.

Shutting the motor off temporarily, if the belt was slipping, would allow the belt to grip the roller again. This is like pumping brakes (now done automatically) when your car starts skidding.

[Paul Johnstone]

When the feed belt stops, you are getting a groove in the board.. My guess is that you are taking off too much in each pass.

One the first pass. adjust the height slowly until you just hear the paper rubbing on the board.. Then take tiny bites. I have a Supermax 37" which is probably comparable in power to your sander.. I only turn the height adjustment maybe 1/16 to 1/8 a turn each pass.

If I am doing several passes, I will occasionally feed the board through at the same height maybe 2-4 additional times, to let the sander "catch up" in case I have gotten too agressive over the accumulated turns.. Listen to the paper hitting the board.. that will give you an idea of how hard the machine is working.

I guess this goes without saying.. but if you have a lot of sanding to do, start off with a course grit to get it close to size, then work your way down to the finer grits. The course grit lets you take bigger "bites" and is less strain on the machine.

[Aaron Hooks]

Paul,

I do get grooves in the board where the drums contact. Perhaps I am taking too much off. I typically crank it 1/8 of a turn. I don't know how the jack screw pitch compares to your unit so it may be taking more than what you do when you turn an 1/8 th.

I will also watch to see if the drive is turning and the belt not!

Thanks much

[Justin Bukoski]

Aaron, an 1/8th is way too much for a sander. I wouldn't even try to take that much off with a planer. Shoot for 1/32 - 1/16 a pass and you be much happier with the results.

[Will Overton]

Aaron, an 1/8th is way too much for a sander. I wouldn't even try to take that much off with a planer. Shoot for 1/32 - 1/16 a pass and you be much happier with the results.


He said 1/8th turn, not 1/8th inch. I generally do 1/8 turn with the 16-32.

[Justin Bukoski]

yeah I really should read more carefully. 2nd or 3rd time I've done that this week....

[Chris Padilla]

If I am doing several passes, I will occasionally feed the board through at the same height maybe 2-4 additional times, to let the sander "catch up" in case I have gotten too agressive over the accumulated turns.. Listen to the paper hitting the board.. that will give you an idea of how hard the machine is working.

I have a Delta 18/36 and sanded up many many veneers that I had resawn. I resawed the walnut to around 3/32" and slowly drum sanded them down to 1/16". Each quarter turn of the sander table adjuster was about 1/64" and I would run the veneer through at least twice...sometime 3 times if I could still hear it sanding a bit for each turn.

It took a very long time to sand all my veneers and was mind-numbingly boring but the results were fantastic. I had 20-24 dead-nuts-on-at-1/16" gorgeous walnut veneers.

So a couple things:

(1) Taking off too much per pass: the sander is NOT a planer.
(2) Feed rate could be too fast: slow it down to allow more time for the sander to remove material but be wary of too slow and heating up the wood too much but not too much of a problem is (1) isn't happening.
(3) Dust collection: you need good strong suction to get all the dust for your health, the paper's longevity, smooth results, and it also serves to cool the wood. All good things...don't skimp here.
(4) PATIENCE Generally, these machines are slow but going slow will usually yield the best results.

[Chip Lindley]

We're waiting...The OP has not clearly stated if the conveyor motor stops? or the belt just stops turning. Big Difference! If the motor indeed is stopping, there may be an overload that is tripping. Evidently, restarting, resets the overload.

Short version: If the motor is tripping, less wood must be taken off. If the conveyor is slipping, tighten it up!

Long version: If the short version does not apply, there may be a problem in the electronics of the variable speed controller, or within the motor itself. That's a whole 'nother can o' worms. You have already replaced the switch and circuit board. Another gear motor may be next.

[Aaron Hooks]

Thanks all.

I am looking for it to stop and then see if the motor is turning or not. Didn't face it today:) I am also preparing myself to go sloow. I appreciate all the feedback. You all are great.

Aaron

[Clint Olver]

I have a general sander. I send each board through twice at 8-12 fpm before turning the crank 1/12 of a turn. Have not had any problems.


C